One option suggested to me by @bmw is
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/SSL-on-an-instance.html#letsencrypt
which describes how to install from EPEL. (However, if you already got the “Unable to find a virtual host” error on the new server, then you already have a working copy of Certbot there.)
Edit: or @bmw says you can try the CentOS instructions on our own site